Landmark basket study is changing how drug trials are conducted

Results have been announced from the first published basket study, a new form of clinical trial design that explores responses to drugs based on the specific mutations in patients' tumors rather than where their cancer originated. The early phase II study of vemurafenib was published in the New England Journal of Medicine (2015; doi:10.1056/NEJMoa1502309).

Basket studies permit the detection of early signals of activity across multiple tumor types simultaneously, while allowing for the possibility that tumor lineage might influence drug sensitivity. The first to follow this model, this new study aims to explore treatment responses among tumors based on their mutation types and to identify promising signals of activity in individual tumor types that could be pursued in subsequent studies. The results will ultimately guide researchers in looking for different drug targets or developing therapies that combine vemurafenib with complementary treatments.

The study, led by Physician-in-Chief and Chief Medical Officer José Baselga, MD, PhD, of the Memorial Sloan Kettering (MSK) Cancer Center in New York, New York, looked at the effect of vemurafenib (Zelboraf) in multiple nonmelanoma BRAFV600-mutated cancers in 122 patients from 23 centers around the world.

Vemurafenib previously has been proven to treat BRAFV600-mutated melanoma. People with lung, colorectal, and ovarian cancers were among those included in the study as well as people with rare diseases, such as Erdheim-Chester disease. Until this point, the efficacy of vemurafenib in nonmelanoma cancers has remained unexplored despite significant therapeutic potential.

"This study is the first deliverable of precision medicine. We have proven that histology-independent, biomarker-selected basket studies are feasible and can serve as a tool for developing molecularly targeted cancer therapy," said Baselga. "While we can, and should, be cautiously optimistic, this is what the future of precision medicine looks like."

Basket studies have the ability to greatly increase the number of patients eligible to receive certain drugs. The mixed efficacy seen in this study proves that drugs can reach patients beyond the current approved use but, expectedly, do not work for everyone. As a pioneering trial, this data demonstrates the promising benefits of basket studies and the need for more work to be done with these types of trials.

The findings illustrate the preliminary clinical efficacy of vemurafenib in multiple nonmelanoma BRAFV600-mutated cancers. Of the 122 trial participants, clinical activity was observed in various tumor types.

"This kind of study is a beneficial way to do rare tumor research because it allows us to open the study to patients with diseases that are completely underrepresented in clinical trials in general, such as anaplastic thyroid cancer and glioblastoma," said first author David Hyman, MD, also of MSK. "By broadening eligibility, we are translating potential benefits to as large a patient population as possible."

This clinical trial is the first in an impending wave of such studies focused on cancer-related mutations identified through the huge amounts of genomic data generated in recent years.